The proposed project is designed to examine the role of nicotine dependence and negative affect on adolescent smoking persistence. These two variables have been shown to contribute significantly to continued smoking in adults, however, it is not known how these variables influence teen smoking behavior. Developing a better understanding of how these variables contribute to the maintenance of adolescent smoking behavior would contribute significantly to the optimal design of adolescent smoking cessation programs. Aim 1 is to assess the construct of DSM-IV nicotine dependence among adolescents who smoke cigarettes. This information will: (a) lead to a better understanding of the impact of dependence on the maintenance of smoking among teens, (b) give an idea as to the prevalence of nicotine dependence among teen smokers, and (c) help to identify those teens that may be appropriate for nicotine-replacement strategies. Aim 2 is to examine the impact of negative affect on successful smoking cessation among adolescent smokers. It is hypothesized that adolescents reporting greater amounts of negative affect upon starting a smoking cessation program will be significantly less likely to be successful in becoming smoke-free upon the termination of the program and at 3 and 6 month follow-up. Finally, the proposed project will provide preliminary information for examining the relationship between substance use severity and nicotine dependence among an adolescent population.